Repeating positive statements such as "I am a lovable person" or "I will succeed" makes some people feel worse instead of raising self-esteem, a study says.
"From at least as far back as Norman Vincent Peale's (1952) The Power of Positive Thinking, the media have advocated saying favourable things to oneself," said the study by Canadian psychologists, which was published in Psychological Science today.
It cites a popular self-help magazine that advises its readers to: "Try chanting: I'm powerful, I'm strong, and nothing in this world can stop me," but says the practice doesn't work for everyone.
Positive self-statements make people who are already down on themselves feel worse rather than better, according to the study conducted by psychologists Joanne Wood and John Lee of the University of Waterloo and Elaine Perunovic of the University of New Brunswick.
For the study, the psychologists asked people with low self-esteem and people with high self-esteem to repeat the phrase: "I am a lovable person," and then measured participants' moods and feelings about themselves.
What they found is that individuals who started out with low self-esteem felt worse after repeating the positive self-statement.
"I think that what happens is that when a low self-esteem person repeats positive thoughts, they probably have contradictory thoughts," Dr Wood told AFP.
"So, if they're saying 'I'm a lovable person,' they might be thinking, 'Well, I'm not always lovable' or 'I'm not lovable in this way,' and these contradictory thoughts may overwhelm the positive thoughts."
Although positive thinking does appear to be effective when it's part of a broader program of therapy, on its own it tends to have the reverse effect of what it is supposed to do, said Dr Wood, urging self-help books, magazines and TV shows to stop sending a message that just chanting a positive mantra will raise self-esteem.
"It's frustrating to people when they try it and it doesn't work for them," she said.